ES2231904T3 - A PUMP AND A FLUID CHAMBER FOR A SET OF NOZZLES. - Google Patents

Abstract

The present invention is directed toward a locking mechanism for aiding in the prevention of accidental or unintentional disengagement of the nozzle assembly from a needleless injection device. In one embodiment of the locking mechanism, a stud positioned on the nozzle assembly engages a recess in the injector to help to deter the nozzle assembly from rotating during firing of the injector. In another embodiment of the locking mechanism, a nib on the nozzle assembly engages a recess in the injector to deter the nozzle assembly from rotating during firing of the injector. A retaining element may be utilized within the injector to provide the recesses for engagement with the locking mechanisms.

Description

A plunger and a fluid chamber for a set of nozzles.

Field of the invention

The present invention is related in general with a plunger according to the preamble of the Claim one.

Background of the invention

Hypodermic injection instruments without Needles have been known and used in the past. These instruments typically use spring or compressed gas pistons to accelerate a fluid at a speed sufficient to pierce the skin and cross the subcutaneous tissues.

Until the 1980s at least, the use of needleless injectors had become more desirable due to the concern of the spread of AIDS, hepatitis and others viral diseases caused by the possibility of accidental "punctures" with syringe needles and conventional needles Needle-free injectors eliminate apprehensions of health professionals and are better in the Elimination of accidental transmission of diseases.

A large number of needleless injectors are known, including U.S. Patents No. 5, 062, 830 of Dunlop, No. 4, 790, 824 of Morrow et al , No. 4, 623, 332 of Lindmayer et al , No. 4, 421, 508 of Cohen, No. 4, 089, 334 of Schwebel et al , No. 3, 688, 765 of Gasaway, No. 3, 115, 133 of Morando, No. 2, 816, 543 of Venditty et al , and 2, 754, 818 from Scherer. These injectors generally include a set of nozzles, which include a medication chamber and a plunger. The chamber has a hole through which the medication is propelled out of the chamber using the piston driven by a piston that is generally connected to some type of energy source.
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Due to the high speed of the propulsion and / or the high pressure of the energy source created by the typical needleless injector, it has been found that the nozzle assemblies have a tendency to disengage during the discharge of the energy source. This fact can result in a dangerous situation, especially if the set of nozzles acts as a projectile. It has been shown that the tendency for this to occur is more pronounced with bayonet installation nozzle assemblies as shown in US Patent Application No. 08/369, 812 of Lilley et al . However, this problem may also exist in screw assemblies. Therefore, a blocking device is needed that prevents the nozzle assembly from unexpectedly decoupling from the injector body.

Nozzle assemblies for injectors they usually include a plunger installed inside the chamber inside the nozzle assembly to move the medication from the set of nozzles (page 1 a). After expelling the medication, it is desirable to release the injector nozzle assembly for your sterilization or disposal.

An added problem associated with the set of nozzles is the tendency of the plunger to remain attached to the piston of the injector after the emission of the power source. For the both, when a set of disposable or reusable nozzles the injection device is released, the plunger must remain connected to the piston In order to avoid possible contamination, the injector plunger must be released for disposal or re-sterilization It is often difficult to release these plungers and sometimes it is necessary to destroy them in the process of withdrawal. It is therefore desirable to provide a plunger that allow easy removal of the injection device and that it can be Detachable with the nozzle assembly.

Summary of the Invention

Therefore, the present invention is related to a plunger that is mobile by sliding inside a fluid chamber The plunger is used to expel the fluid outside or to introduce the fluid into the chamber by moving the piston relative to the camera.

The plunger includes a main body and a group of arms curved outward. The body has a distal end and a proximal end. The fluid is expelled out and conducted inside the chamber through the distal end. The arms are located at the proximal end and are operatively associated With a force generating component.

The camera can also have distal ends and proximal ends with an adjacent outward flare to the proximal end. This part flared out is configured and sized to accommodate the curved arms towards outside to allow the emission of the force generating component from the arms

The arms may also include an edge in a internal surface and an edge on an external surface. When the edge is used, the flared part out of the chamber It also includes an annular groove to receive the edge. The edges are used to engage the force generator component when the arms are positioned in the chamber.

In another embodiment of the present invention, a set of nozzles adapted for use with a injection mechanism includes a chamber, a generator component of force and a plunger, such as those of the first and second realization. The chamber contains the fluid and has a hole for the channeling of the fluid at one end. The generator component of force is to generate the force that expels the fluid towards outside or to introduce the fluid into the chamber.

Brief description of the drawings

The preferred features of this invention are discovered in the accompanying drawings, where characters of similar reference denote elements similar to through different views, and where:

Fig. 1 is an elevated view of one side of a injector head with internal thread incorporating the closing mechanisms of the present invention;

Fig. 2 is a perspective view of a retention element for use with an injector head that incorporates the closing mechanisms of the present invention;

Fig. 3 is a side view of a section cross section of an injector body that includes an element of retention to receive a nozzle that incorporates the mechanisms of closure of the present invention;

Fig. 4 is a top elevational view of a injector head with internal thread incorporating the closing mechanisms of the present invention;

Fig. 5 is a side view of a section cross section of the injector head shown in Fig. 1;

Fig. 6 is a rear view of the tip of the injector head showing the indication pins to both sides;

Fig. 7 is a cross-sectional view of bayonet assemblies of the nozzle assembly;

Fig. 8 is a top elevated view of the retaining element of the present invention, shown in Fig. 2;

Fig. 9 is an elevated side view of the retaining element of the present invention, shown in Fig. 2;

Fig. 10 is a cross-sectional view of the element of retention taken along the 10-10 plane as is shown in Fig. 8;

Fig. 11 is a cross-sectional view of the element of retention taken along plane 11-11 as is shown in Fig. 8;

Fig. 12 is a partial cross-sectional view of an embodiment of the plunger of the present invention.

Fig. 13 is a cross-sectional view of one of the arms on the plunger of Fig. 12;

Fig. 14 is a view of a proximal end of the plunger shown in Fig. 12;

Fig. 15 is a cross-sectional view of the plunger in area 15-15 as shown in Fig. 12;

Fig. 16 is a cross-sectional view of the plunger installed in the internal chamber of the nozzle assembly after that the injector has been fired and the injector piston has been retired;

Fig. 17 is a partial cross-sectional view of another embodiment of the plunger in the present invention;

Fig. 18 is a cross-sectional view of one of the arms on the plunger of Fig. 17;

Fig. 19 is a view of a proximal end of the plunger shown in Fig. 17;

Fig. 20 is a cross-sectional view of the plunger in the 20-20 area as shown in Fig. 17;

Fig. 21 is a cross-sectional view of the piston of Fig. 17 installed in the internal chamber of the nozzle assembly before filling the chamber with medication.

Fig. 22A is a cross-sectional view of the plunger of Fig. 17 installed in the internal chamber of the assembly of nozzles after the injector has been fired;

Fig. 22B is a cross-sectional view of the plunger of Fig. 17 installed in the internal chamber of the assembly of nozzles after the injector has been fired, the set of nozzles has turned towards the opening position and the piston is about to be removed; Y

Fig. 23 is a sectional view of the area 23-23 of Fig. 22 of the proximal end of one of the piston arms in cross arrangement with the inner chamber of the nozzle assembly as the injector piston is withdraw

Detailed description of the embodiments preferred

The exterior of the nozzle assembly 10 is shown in Fig. 1, with various embodiments of the device blocking of the present invention installed therein. An element retaining 20, or retaining ring is shown in Fig. 2. The The present invention uses a nozzle assembly 10 that incorporates  a locking device in conjunction with an element of retention 20 in an injector 30. This combination will prevent a Unexpected decoupling of the nozzle assembly 10 from the injector 30

An injector 30 is shown in Fig. 3 with the retaining element 20 disposed within the injector 30 relative to the distal end thereof. The nozzle assembly 10 is generally installed at a distal end of the injector 30. The injector 30 is shown for illustration purposes only, since the present invention is not intended to teach someone skilled in the art how to make an injector. For this purpose, US Patent Nos. 5, 599, 302 of Lilley et al. Can be used for an injector with a spring-loaded gas energy source. It should be emphasized that any type of injector can be used with the locking device of the present invention. Likewise, any type of energy source can be used with the present invention, such as spring-operated gas, spiral spring or compressed gas. Also, the nozzle assemblies contemplated for use with the present invention can be both disposable and reusable.

As used in this application, the "distal" or "frontal" terms will designate the end or direction towards the nozzle assembly 10 of the injector 30. The "proximal" and "posterior" terms will designate the end or direction to generator 32. The term "longitudinal" designates an X-X axis that connects the set of nozzles 10 with generator 32, and the term "transverse" designates a direction fundamentally perpendicular to the address longitudinal including the arches along the surface of the injector 30.

Referring again to Fig. 1, it represents a set of nozzles of the present invention. He nozzle assembly 10 has a tubular body and includes a tip 12 at the distal end and a tail 14 at the proximal end. The nozzle assembly 10 also includes a plurality of threads 16 arranged in the body of the nozzle assembly 10 between tip 12 and tail 14 and a bypass passage 18 located between threads 16 and tip 12.

The threads 16 are preferably in a pattern partial helical around the circumference of the body tubular nozzle assembly 10. The threads 16, when they are in partial helical pattern, they form segments in rib 16. rib segments 16 are preferably elevated in a angle? which preferably varies between 0º and 7º, being Preferably a variation of 0º to 3º, as shown in Fig. 1. The angle? Is measured from a plane drawn in perpendicular to the X-X axis of the nozzle assembly 10. The segments in rib 16 are spaced apart and relative to others and are preferably at a predetermined distance. The distance determines the axial travel speed of the set of nozzles when the rib segments are rotated defining the space between the segments in rib 16. The distance is preferably .08 inches per thread, but they can vary to a range of .04 to .2 inches per thread. It has been found that the nozzle assembly is more likely to be disengaged or unscrew when the distance and angle? is larger, such as at an angle of 7º and 0.1 inches by distance of thread. Therefore, a greater angle? And distance will have a greater probability of decoupling.

The tail 14 is for insertion at one end distal 34 of an injector 30. When the tail 14 is inserted inside the injector body 30, the rib segments 16 are housed by the corresponding grooves 36 inside the injector 30, therefore the rib segments 16 and the tail 14 they are housed with the injector after insertion and rotation. When the rib segments have been inserted and rotated correctly, Then they are in their final position.

The segments in rib 16, as shown in Fig. 1, are bayonet type installation. They can also be used conventional screw type threads. When queue 14 and the rib segments 16 are inserted into the injector 30, the nozzle assembly 10 is rotated to couple the segments in rib 16 mounted on bayonet with grooves 36 inside of the injector 30. The bypass passage 18, being of a diameter greater than the segments in rib 16 and tail 14, rest then at a distal end of the injector 30.

Referring to Figs. 1, 4 and 7, the segments in rib 16 preferred to connect to the injector 30 are in 90º angle, that is, they are located substantially ¼ of the circumference of the body on the opposite side. It is preferable that the proximal end or thread 17 is transversely wider than The other slots. It is also preferable that the segments in rib 16 remaining are of the same transverse width, Although not required. Tooth 17 is wider than the rest teeth in order to ensure that the nozzle assembly 10 is completely inserted into connector 30 before being rotated to the locked position. Because the grooves 36 in the injector 30 are preferably sized to accommodate the segments in rib 16, the most proximal groove that houses the segments in rib 16 is preferably wider than the remaining grooves. Therefore until the nozzle assembly 10 is not completely inserted into the injector 30, it is difficult, if not impossible, rotate the nozzle assembly 10 towards a position of blocking.

Additionally, the most distal groove 19 is preferably half-slot. By half-slot means a slot 19, is located substantially half of the set circumference of nozzles 10. This slot 19 interferes with the most distal edge 21 associated with slots 36. Since slots 36 are preferably arranged on opposite internal sides of the injector 30, the half-slot 19 cannot pass through edge 21. In this way, the set of nozzles 10 be inserted too far from the distal end of the injector 30. The combination of wide tooth 17 and long tooth 19 It helps to ensure that the nozzle assembly 10 is correctly positioned inside the injector 30 before Shooting.

Then, as shown in Fig. 7, it is has discovered that the cross-sectional dimension of the segments in rib 16 is important, but not critical, for the present invention. The preferred type of tooth 16 for installation in Bayonets are what are generally referred to as threads of buttress. These threads are preferable when it is required that the threads house a large longitudinal load. Type threads buttress also help the segments in rib 16 be fold when they are under the load. As shown in Fig. 7, buttress threads 16 preferably have an edge distal, which is preferably substantially perpendicular to the longitudinal axis X-X (Fig. 5) with a part flat top that is substantially parallel to the longitudinal axis X-X and an angled proximal edge. The gradient of distal angle is preferably approximately 10 ° from the perpendicular. The angled proximal edge is preferably of 90º, measured from the plane of the surface of the upper part flat, but may vary preferably in a range of 20º to 40th.

As depicted in Figs. 1, 4 and 5, the nozzle assembly 10 has a longitudinal body that defines a chamber 40 communicating with a hole 42 at the distal end of the nozzle assembly 10. Fluids such as a medicine Liquid can pass into chamber 40 through hole 42. Also the fluid can be extracted from the hole 42 during the injection process The body of the nozzle assembly 10 is generally cylindrical and, at its distal end, has a tip cone 44 with hole 42 centrally located at tip 44 preferably along the longitudinal axis X-X of the nozzle assembly 10. A cylindrical sleeve 46 extends proximally from the rear end of the conical tip 42.  Following the sleeve 46 in the proximal direction is the passage of branch 18, which can be used to connect the assembly of nozzles 10 to an adapter (not shown), a cap (not shown) or any other device that is suitable for joining the tip end of a set of nozzles. The passage of branch 18 preferably includes a group of grooves 48 which are configured and sized to fit with another instrument, of the type mentioned above. The passage of bypass 18 also preferably includes a pin of indication 50 extending out to each side of the passage of bypass 18. The indication pin 50 will be explained carefully later.

The slits 48 in the bypass passage 18 they can be of any type that allows the connection of a set from 10 nozzles to another instrument. Following the derivation step 18 in the proximal direction are the segments in rib 16 which they are followed by a tail portion 14. The tail portion 14 includes the blocking devices of the present invention.

It has been discovered that due to the high speed of propulsion created when the injector fires, the set of nozzles 10 has a tendency to disengage by unscrewing during the broadcast

This effect is more pronounced when used. bayonet type assemblies, as shown in Figs. 1 and 4, but it can also occur in conventional type assemblies screw. It is desirable to have an inhibition or blocking mechanism of the injector in order to avoid unintended decoupling or accidental set of nozzles. The present invention is indicated in various mechanisms to block the set of nozzles in position during the broadcast.

A first embodiment of the device lock is in the use of a rod 52 that protrudes from the outer circumference of the tail portion 14 of the set of nozzles 10. Two rods 52 are preferable, as shown in Fig. 5, although a single rod 52 can be used effectively. The two rods are preferably placed on opposite sides. of the tail 14. When the tail 14 is inserted into the injector 30, the rod 52 is engaged in a cavity 54 inside the injector 30. This cavity 54 can be supplied by the element retention 20, as will be detailed precisely below.

It is preferable that, when tail 14 and rib segments 16 are inserted into the injector 30 and rotate to introduce the segments in rib 16 within the slots 36, allow rod 52 to move through the cavity 54 until you reach an anchor 56. Rod 52 moves preferably in the longitudinal direction at the same rate as the ribbed segments 16. When rod 52 has moved until anchor 56, the nozzle assembly 10 has been fixed completely inside the injector 30 towards the final position of blocking. When rod 52 reaches the final locking position, the user preferably receives the positive response that the set of nozzles has been closed. This positive response It can be a click sound or a touch reaction. After arriving at the locked position, the user also preferably notices a decrease in resistance, knowing that it has reached the correct and final closing position.

A second embodiment of the device blocking is found in the use of tips or projections 58 which extend proximally and longitudinally from tail 14 of the nozzle assembly 10. Although two tips 58 are preferable, You can use one effectively. Tips 58 are preferably arranged on opposite sides of tail 14, as shown in the Fig. 4. More preferably, tips 58 are positioned at 0 ° and 180º while rods 52 are at 90º and 270º. When the glue 14 is inserted into the injector 30, the tips 58 are coupled in cavities 60 inside the injector 30. The cavities 60 can be included in the retention element 20, which is placed inside the injector 30.

It is preferable that, when tail 14 and rib segments 16 are inserted into the injector 30 and rotate to introduce the segments in rib 16 within the grooves 36, tips 58 are slightly depressed and move along the inner surface of the injector 30 until it is attach to cavity 60.

A transverse groove 64 is placed preferably adjacent to tips 58. This groove 64 allows tips 58 to have protective characteristics anti-deformable If plastic or a similar flexible material for the nozzle body, it is possible use tip 58 without slit 64. However, to allow the tips 58 to flex inwards, it is desirable arrange the slits 64 near the tips 58 to allow the tips 58 flex slightly inwards until reaching the cavity 60. The tips 58 reach the final locking position when they enter cavity 60. When tips 58 enter the cavity 60, the nozzle assembly 10 has been screwed completely inside the injector 30. When the tips 58 reach the final lock position 60, the user preferably receives the positive response that the set of nozzles has remained closed. This positive response can be a click sound or a tactile reaction Once the blocking position is reached, the user also preferably notices a decrease in resistance, knowing therefore that the position has been reached Correct and final closing. The tips 58 are preferably rounded, which helps in its movement inside the injector 30, before reaching the final blocking position.

Both tips 58 and rods 52 have sufficient protection characteristics anti-deformable as to allow the whole of nozzles 10 be unscrewed from the injector 30.

According to the preferred embodiment of the present invention, the nozzle assembly 10 mentioned previously it is formed entirely of metal and preferably stainless steel. This type of nozzle assembly 10 is generally reusable Another preferable embodiment of the set of nozzles 10 is formed entirely of plastic. This type Nozzle assembly 10 is generally disposable. Can be use other materials to make a set of nozzles 10. The Preferable plastic is a polycarbonate, such as Makrolon, manufactured by Bayer.

Another feature of the present invention is the use of indication methods to correctly position the set of nozzles 10 inside the injector 30. The set of nozzles 10 may preferably include two indicators different 50, 66, although it is possible to use a Only indicator without the other. Injector 30 must also include preferably another indicator 68 that is used in conjunction with the indicators 50, 66 in the nozzle set 10 for linear correctly the set of nozzles 10. The indicator 68 of the injector 30 is located along the edge 70 'of the injector 30 in a distal end This indicator 68 may be a mark or border which extends outward, but a marker is preferable, such as a highlighted line or a square, as shown in Fig. 3, in translucent view. The indicator 68 on the injector 30 works in conjunction with indicators 50, 66 in injector 30. These indicators 50, 66, 68, are necessary because the sets of nozzles are routinely removed from injector 30. By means of provision of indicators, the set of nozzles 10 can be easily align by inserting correctly into the injector.

There are two other types of indicators provided in the nozzle assembly 10. The first indicator 66 can be place on the side of the circumference of tail section 14 or preferably on two sides. This indicator can be recorded inside of the tail 14 of the nozzle assembly 10 or mold inside the queue 14 as a high indicator 66. Indicator 66 shown in the Fig. 1 is in the form of "A", but it can be of another type or indication marker such as a point.

The second indicator 50, as mentioned above, it is preferably located in the step of bypass 18, and is disposed at the proximal edge of the passage of bypass 18. this indicator 50 preferably extends towards outside from bypass step 18.

The first indicators 66 are preferably located at the same angle of rotation as tips 58 and second indicators 50 are preferably located therein rotation angle than rods 52. Therefore, the first 66 indicators are preferably at 0º and 180º and the seconds 50 indicators are located at 90º and 270º. However, the space of the indicators is determined by the difference in position between the coupling or entry point of the nozzle assembly inside of the injector and the locking point. Therefore, the indicator means that it can be used independently of a method of closure, such as the rod and the cavity. For example, you can use an indicator method to show the user how to insert the set of nozzles inserting the tooth in installation type bayonet inside the injector, and after the rotation of the set of nozzles, can be used to indicate that the set of Nozzles have already rotated completely.

In operation, the first indicator 66 is preferably aligns with the injector 68 indicator and is Insert the nozzle assembly 10 into the injector 30. Then the set of nozzles is rotated to couple the ribbed segments 16 with grooves 36 and the devices of lock 52, 58 with cavities 54, 60. When the set of nozzles 10 has been completely screwed in such a way that the locking devices 52, 58 engage with cavities 54, 60, the second indicators 50 will align with the indicators of injector 68 to indicate to the user that the nozzle assembly 10 has been properly installed in the injector 30.

As discussed above, it can be used a retaining element 20 in the injector 30 to work in conjunction with the locking devices 52, 58. A retention element 20 because it can be realized in metal such as stainless steel, while injector 30 is It can be made in a more flexible material, such as plastic. A retention element made of metal provides locking devices a strong surface on which lean on. As such, it provides greater protection in a unexpected decoupling. A retention element made in metal is less likely to fail than an injector body conventional plastic. The retention element made in metal is also appropriate because it can be easily inserted into an injector 30 with a limited number of modification in the injector 30. The retaining element 20 is shown in perspective in Fig. 2 and in elevated view in Fig. 8 and 9.

The retaining element 20 is preferably a cylindrical body having a distal end 22 and an end proximal 24. As shown in Fig. 3, the retaining element 20 is preferably fixed near the distal end of the body injector. The retaining element 20 can be adjusted with the injector 30 placing this behind an annular groove 26 in the inside the injector 30. The generator 32 is then placed in a zone next to the retaining element 20. The tail 14 of the assembly of nozzles can be inserted into the distal end 22 of the retention element 20. Therefore, the retention element 20 It is preferably sized to accommodate the tail portion 14 of the nozzle assembly 10.

Preferably there is a wall 28 located in the proximal end 24 of retaining element 20. Wall 28 preferably includes an opening 70 to receive the piston 72 (shown in Figs. 14 and 15) of injector 30, as shown in Figs. 10 and 11. Piston 72 accepts power from generator 32 for driving the medicine out of the inner chamber 40 of the assembly of nozzles 10. Therefore, the opening 70 in the wall 28 is sized to accept piston diameter 72.

The wall 28 also includes at least one cavity or slot 60 to house the second locking device, the highlight 58. As shown in Figs. 10 and 11, slots 60 go perpendicular to the longitudinal axis X-X of retaining element 20 in the wall 28. As shown in the Fig. 2, 8 and 9, the retaining element 20 also includes inputs 65 to facilitate the matching of slots 60. The grooves extend from the outer circumference of the element retention 20 to opening 70 in wall 28. When they use two projections 58 in the set of nozzles 10, the slots 60 are preferably asymmetric, or axially spaced of the center line of the opening 70. The cavities 60 are asymmetric to offer a rapid fall for the entrance of the highlight 58 in cavity 60. Cavities 60 are rotated preferably 180º next to each other in wall 28 to accommodate projections 58, which are also preferably turned 180º next to each other. However, if you highlight them 58 Slots 60 are not located next to each other, slots 60 they will preferably be at the same radial angles as the Highlights 58.

The retaining element 20 also includes a cavity 54 to receive the first locking device, the rod 52. This second cavity 54 is preferably in shape of slit in L. A first inlet 72 'of the slit is extends axially from the distal end of the element of retention 20 partially along the length of the element of retention 20. A second inlet 74 of cavity 54, extends from the end of the first slit at an angle in K in helical pattern This angle k is preferably at the same distance and angle? that the partial helix of the segments in rib 16 of the nozzle assembly 10. The angle k allows the rod 52 move axially at the same rate as the ribbed segments 16. An anchor 56 is located on the other end of the second inlet 74 to accommodate the rod 52 in the closing position

In operation, when both rod 52 as the protrusions 58 are used in the nozzle assembly 10, the nozzle assembly 10 is inserted into the injector 30 and the retaining element 20, such as rod 52 is aligned with the first entry 72 'of the cavity 54 with an L-shape. When the nozzle set 10 is fully inserted longitudinally within retaining element 20, this is rotated to allow segments in rib 16 to rotate from bayonet type in the corresponding grooves 36 in the injector 30, as shown in Fig. 3. The second entrance 74 of the cavity 54 has dimensions such that there is a slight bond to pressure between the nozzle assembly 10 and the retaining element 20 when the segments in rib 16 are introduced by rotation in the grooves 36. When the nozzle assembly 10 broken, the rod 52 moves along the second inlet 74 of the L-shaped cavity 54 until it is introduced into the anchor 56. When rod 52 is inserted into anchor 56, the nozzle assembly 10 must have completely rotated so that the ribbed segments 16 and the grooves 36 engage. When rod 52 reaches anchor 56, the user preferably perceives a clicking sound or a tactile sensation that indicates that rod 52 has entered anchor 56. This tactile sensation It will be of reduced resistance. Once the rod 52 is located at anchor 56, the first locking device 52 is couples and prevents the nozzle assembly 10 from decoupling during the shot of the injector 30. In addition to offering a position of closure, the L-shaped groove helps ensure that the set of nozzles are correctly inserted and located in the injector. Therefore, the L-shaped groove also helps prevent a incorrect coupling of the nozzle assembly in the injector.

Regarding the second locking device 58, when the nozzle assembly 10 rotates within the element of retention 20 to couple the segments in rib 16 with the slots 36 in the injector 30, the protrusions 58 have resistance against the inner part of the wall 28. As the segments in rib 16 are rotated, this resistance increases. When the groove 64 is in the tail 14 of the assembly of nozzles 10 adjacent to projections 58, the projections will be twisted slightly inward enough to allow the nozzle assembly 10 rotate completely within the element of retention 20 and injector 30. When the segments in rib 16 they reach the end of their displacement path within the slots 36, the projections 58 enter the cavity 60 located in the inner side of the wall 28, therefore when the set of 10 nozzles have completely turned to their final position, the Highlights 58 will be placed in cavities 60. This device blocking helps prevent the nozzle assembly 10 from disengaging unexpectedly during the broadcast, since it prevents the nozzle set 10 rotate. The combination of the two mechanisms lock 52, 58 used simultaneously, also helps ensure that  the nozzle assembly 10 does not disengage. This combined with the use of optimized threads in bayonet 16 will also help I will avoid an unexpected decoupling.

Fig. 12 shows a first embodiment of the design of an improved plunger of the present invention. Piston 80 it is generally located in the internal chamber 40 of the set of nozzles 10, as shown in Fig. 16. As shown more clearly in Fig. 21 for a second embodiment of the plunger  80, when the nozzle assembly 10 is attached to the injector 30, the piston 80 is fixed to piston 72 of injector 30. Piston 72 connects to power supply 32, so that when the power supply 32 trips, piston 72 moves the plunger 80 to release the medicine from the inner chamber 40 through the hole 42.

After the injector 30 has been fired, the plunger 80 moves to the distal end of the chamber 40. With the purpose of recharging the power supply and replacing the nozzle assembly 10, piston 80 must be removed from the piston 72 so that a set of sterile nozzles can be reinstalled. A problem with the previous plungers has been discovered, since it was often difficult to remove them from piston 72 after the emission, so that when the nozzle assembly of the injector 30 was removed, the piston 80 remained attached to the piston. As a result, the pistons had to be removed manually, by force or destroying them The present piston design and nozzle assembly mitigate this problem by supplying outward curved arms or legs 82 in the plunger 80.

As shown in Fig. 12, the plunger 80 of the present invention includes a distal end and an end proximal

The plunger 80 is preferably cylindrical of shape and is sized to fit perfectly, although allow sliding inside the inner chamber 40 of the nozzle assembly 10. Tip 84 of plunger 80 is located at the distal end and is preferably designed so that substantially match the internal contours of the chamber internal 40 of the nozzle assembly 10 at its distal end. He plunger 80 preferably includes a seal 86 adjacent to the tip 84. Seal 86 helps prevent medication from passing through the seal 86 before or during the issuance of the injector 30. Seal 86 it is preferably compressed during use to offer a tight fit inside the inner chamber 40, as shown in Fig. 16.

A group of arms or legs 82 are located in the proximal end of the plunger 80. The arms 82 are for fixing to the piston or clamping cylinder 72 of the injector 30. The arms 82 of the present invention are normally curved or flexed out, but they are flexible enough to bend in the opposite direction to its normal position so that the plunger 80 can slide into the chamber 40. As is shown in Fig. 14, four arms 82 are preferable, although you can use another number of arms 82. One end 88 of the piston 72 preferably has the form to connect with the arms 82 of the piston, as shown in Fig. 21. Each arm 82 includes a edge 90 to surround the end portion 88 of the piston 72. Each arm 82 is preferably separated at uniform angles around the outer circumference of the plunger 80. The plunger 80 it also includes a stop 92 that is located along the axis longitudinal X-X of the centrally located piston 80 between arms 82. This stop 92 is a contact stop with the piston 72, when the power supply 32 trips. When the power supply 32 trips, piston 72 moves moving away until you contact the top 92, at which point the piston 80 and piston 72 move in unison to release the medicine from the inner chamber 40 through hole 42. If the piston end portion 72 is substantially the same length that the distance between the edges of the arm 90 and the stop 92, the piston 72 will not move longitudinally relative to the plunger 80. If the end portion 88 of the piston 72 is smaller than the length of distance between the edges 90 and the stop 92, the piston 72 will move longitudinally relative to piston 80 until contact the top 92.

The arms curved out of the plunger 80 they can be shorter than the length of the plunger 80 and extend to the proximal end of it. The edge 90 is located at the proximal end of the arms 82, as shown in view cross section exploded in Fig. 13. The proximal end of the spike 82 preferably includes several sloping surfaces. A first slope surface 91 is preferably in a angle Δ of approximately 20 °, but may vary from 0 ° at 40º. This surface helps the piston to disengage from the piston 72. A second slope surface 93 is preferably at an angle E of approximately 30º, but it can vary from 0º to 90º. The second sloping surface is provided to help at the end 88 to be introduced into the proximal end of the plunger 80 to join with the edges 82 when a set of nozzles 10 inside the injector 30.

Fig. 15 shows a cross view of the plunger 80 in the area 15-15. In this situation, the plunger 80 It is cylindrical and preferably has a cross section circular with cavities 81 that form an X or cross shape. Yet side, the cross-section has a shortened arm 83 with a protrusion extending outward 85. Because the plunger 80 is generally manufactured by molding, cavities 81 and The reduced arm 83 is used in the molding process. The cavities 81 must be separated from the central core to reduce the piston retraction. The reduced arm 83 is used as the point of  connection with the mold and the projection 85 is a point where the Plunger is released from the mold. By supplying the arm reduced 83, no additional surface finish is required of the piston after separation of the mold.

The internal chamber 40 of the nozzle assembly 10 includes a decreasing part 96 at the proximal end to receive the arms curved out 82, as shown in the Figs. 5 and 16. This decreasing part 96 is preferable to be narrow enough to allow the piston arms 82 80 adjust to the transition and allow piston 72 to release from piston 80 after emission.

In operation, the plunger 80 rests inside of the inner chamber 40 such that the arms 82 are they compress inwards in the opposite direction to their curvature towards outside. After the injector 30 is fired, the plunger 80 is placed at the distal end of the internal chamber 40. To rearm the power supply 32 and replace the nozzle assembly 10 for the next injection, the piston 72 moves away. To the extent that piston 72 moves away and piston 80 reaches the decreasing part out 96 of the internal chamber 40, as shown in Fig. 16., the arms curved out 82, are curved out to assume your relaxed position and enter the decreasing part 96. Because the arms are allowed to bend outward towards its relaxed position, there is a free space for edges 90 of arms 82 stop fitting with end 88 of piston 72. As a result, piston 72 is easily released from the 82 arms of the plunger. When the nozzle set 10 is disengage the injector 30, the plunger 80 remains with the assembly of nozzles mitigating the problem that previously existed with the piston 80 preventing its release from piston 72.

The plunger 80 of the first embodiment is preferably constructed of plastic material, although they can be Use other materials. Plastic is usually chosen when The plunger is disposable. The preferred plastic materials include the following polymers: poly carbonate, acrylic, polypropylene and poly styrene.

A second embodiment of plunger 80 is shown in Fig. 17. This plunger 80 exhibits the same characteristics as the plunger shown in Fig. 12, but also includes a part fragmentable 100. Plunger 80 includes a distal end and a proximal end and is preferably cylindrical in shape and is sized to fit perfectly, even if it allows sliding inside the inner chamber 40 of the set of nozzles 10. Tip 84 of plunger 80 is located at the end distal and is preferably sized to match substantially with the internal contours of the internal chamber 40 of the nozzle assembly 10 at its distal end. Piston 80 preferably includes a seal 86 adjacent to tip 84. The seal 86 helps prevent medication from passing seal 86 before or during injector 30 trip. Seal 86 is preferably compressed during use to offer an adjustment tight inside the inner chamber 40, as shown in Fig. 16.

The group of arms or legs 82 are located in the proximal end of the plunger 80. The arms 82 are normally curved out. One end 88 of the piston 72 is sized preferably to connect to the piston arms 82 as shown in Fig. 21. Each arm 82 includes an edge 90 for surround the end portion 88 of the piston 72. In addition to including a edge 90 on its inner surface, arms 82 include a edge 94 on its outer surface. Both edge 90 and edge 94 are located at the proximal end of the arms 82, as shown in the cross-sectional view in Fig. 18.

Edge 94 is associated with the annular groove 98 in the decreasing part 96 at the proximal end of the assembly of nozzles 10, as shown in Fig. 21-23. The slot 98 is preferably located near the most part wide of the decreasing part out 96 and is sized to receive edge 94. This slot 98 and edge 94 help to prevent the piston 80 from entering the assembly of nozzles 10 before the piston 72 engages the stop 92. When sufficient pressure is applied to the stop 92 by the piston 72,  the arms 82 will be disengaged from the slot 82 to allow the piston 80 moves distally and therefore arms 82 and the edges 92 fit into the end 88. The slot 98 also preferably includes a beveled proximal edge 99 that is supplies to facilitate manufacturing. The proximal edge beveled 99 is preferably at a slope angle? which is approximately 45º relative to the longitudinal axis X-X, although the angle? May vary from 0º to 90º.

As shown in Fig. 17 and 20, plunger 80 of the second embodiment is fragmentable. The use of a fragmented piston, as in US Patent No. 5, 643, 211, which It is incorporated herein for reference. The plunger 80 has a first motor member 110 and a second motor member 120. How to sample, these members generally have cylindrical shape and a specially shaped base 112, 122, and ends 114, 124. Although a plunger with a D-shaped end and base can be used, it is preferable to use a modified D form where portions of the curvilinear part of D have been removed, as shown in Fig. 20. These drive members 110, 120, are connected to each other in separate relationship through a separation Default via a fragmentable connection or bridge 100.

As shown in Fig. 17, the bridge Preferred fragmentable 100 is a relatively narrow part, superimposed and connecting the first and second motor member 110, 120. It is preferable that the height of the fragmentable bridge be minimal to offer a localized cutting area. The fragmentable part 100 must be arranged adjacent to both smooth sides of the ends 114, 124, of the first and second driving members 110, 120. A leading or distal edge 111 of the fragmentable part 100 is preferably rounded, defining a radius. This radio is defined to offer a clean break of two parts, which allows the second driving member 120 to close the space G between the first motor member 110 and the second motor member 120.

In addition, cavities 123 are defined in a end of the channels that define the fragmentable part 100. These cavities are located at bases 112, 122, adjacent to the 100 fragmentable part, and are configured and sized to accept the burr or residue that can leave the fragmentable bridge 100 during the break. Cavities 123 are offered to avoid any interference between the emission and the movement of the first motor member and the second motor member 110, 120.

The fragmentable part 100 is preferably separated by a small distance from the longitudinal axis X-X in order to offer a fragmentable connection acting break when an amount of force is applied enough. Preferably, the plunger 80, which includes a bridge fragmentable is made of plastic and is configured and sized as such fragmentable part 100 to support a force "p", to move or remove the plunger and drive the Liquid medication inside chamber 40 without rupture. Usually,  an acrylic polymer will offer the necessary strength to withstand  medication loading or filling procedures, but it is also fragile enough to break when the force of issue. The current fragmentable part 100 is designed to act of rupture when the force "P" is applied, which is superior by force "p".

Alternatively, the plunger can be used fragmentable 80 with a preloaded camera 40, thereby eliminating the need to move the plunger lengthwise to introduce liquid medication inside the chamber or expel excess of liquid or bubbles thereof.

The end of the first driving member 110 includes seal 86, in the form of an "O" ring or the like, preferably formed around its outer periphery to offer a seal with the inner wall of the chamber 40. The plunger 80 by itself can act as a seal. Other stamps or parts of a seal can be included at the exit end of the second member 120 drive if desired to provide a better seal to avoid the leakage of liquid from the chamber minimizing the entry of air into the chamber from around the first and second motor member 110, 120 and preventing air from entering the hole 42 due to the liquid leakage from the chamber around the limbs motor.

As part of the filling operation, the plunger 80 is pushed into chamber 40, distally to bleed air from the internal chamber, as shown in Fig. 21. As the plunger 80 is attracted in the proximal direction, it performs a partial vacuum inside the chamber and medication liquid is introduced into chamber 40 through the hole 42

It is stated that the fragmentable connection it has the dimensions and is configured so that said action Push or pull requires a "p" force normally associated with the slow withdrawal or expulsion of air or medication prior to injection, do not break bridge 100. After application of  a relatively large injection of "P" force in the piston, which can be significantly greater than the "p" force, the piston transmits this force "P" to the second drive member 120 and breaks the fragmentable portion 100. This allows the second motor member 120 close space G and transmit force to the first  driving member 110 so that the respective base 112, 122 and the ends 114, 124 join to expel the medication out of the chamber 40. Specifically, end 114 of the second member drive 120 contacts base 112 of first drive member 110 while the base 122 of the second driving member 120 contacts with the end 124 of the first driving member 110 to drive the first drive member 110 through the hole 42 of the chamber to expel the fluid from it.

Fig. 22 A shows the position of the plunger 80 after the injection is complete and all the medication It has been ejected. In this position the break zone 100 has broken so the first motor member 110 and the second member drive 120 are in contact and the plunger 80 is located in the distal end of chamber 40.

Finally, Fig. 22 B shows the position of the plunger 80 after the injection is completed and the nozzle assembly 10 has been rotated or disengaged from the injector. The nozzle assembly 10 has been rotated so that the segments in rib 16 they are free of injector 30 and can be removed. In this point, as the nozzle assembly 10 is removed or has receded from injector 30, piston 72 and the second member motor 120 approach inside chamber 40 until the arms curved out 82 hook the decreasing part 96 of the set of nozzles 10. When this hitch occurs within the decreasing part 96, the piston 72 is released from the arms 82 and the nozzle assembly 10 can be completely removed from the injector 30. Then the first driving member 110 and the second driving member 120 remain within the nozzle assembly 10 and they are easily removed from the injector 30 and the nozzle assembly 10 therefore it can no longer be reused and must be discarded. It prevents unwanted reuse of the nozzle assembly.

In normal operation of the injector, the piston 72 of the injection apparatus operatively connected to a power supply 32 imparts a sudden force or impact "P" to the second driving member 120, sufficient to drive the second motor member 120 within the first member 110. This action is enough to drive the liquid contained in the chamber 40 out through hole 42 as a pressure of peak flow for example greater than 5,000 psi out of the hole 42. This sudden force "P" is capable of breaking the bridge 100 fragmentable before the injection begins. Specifically the force "P" applied to the second member motive 120 is transmitted to the first motive member 110 through the bridge 100. Initially the frictional force in the seal 86 generates enough friction to momentarily prevent the Plunger 80 move. Once this frictional force has finished, the piston 80 begins to move and imparts pressure to the medication in chamber 40. This creates resistance or pressure from return on the first motor member 110. When the difference between the resistance force imparted to the first motor member 110 by the fluid and force imparted by the second member drive 120 towards the first drive member 110 reaches a level default, bridge 100 is broken and the second driving member 120 is propelled into the first driving member 110.

Alternatively, the fragmentable bridge 100 can be broken by an intermediate force larger than the force "p", before a relatively large injection force "P" is applied to piston 72. Said intermediate force can be generated for example by a pressure exerted on the liquid contained in chamber 40 through hole 42 or through another activation mechanism

The "G" space plays an important role creating the proper pressure peak necessary to drill through of the patient's skin. A change of space "G" will change the initial force imparted in the first motor member 110. The pressure peak may therefore vary with the "G" space. It may also vary depending on the viscosity of the medication, injection penetration depth, and others parameters that could affect the outlet pressure of the initial injection A person with ordinary knowledge in the matter can determine by routine experimentation the optimal space for a rupture piston that is used with a particular medication

Advantageously, the fragmented plunger 80 or the set of nozzles 10 or both can be manufactured in different colors, where each color denotes a width default e space G. This color code scheme help the user to choose the right set of nozzles for A specific application. In addition, the amount of force to breaking the bridge 100 can be adjusted by changing the dimension of the bridge 100.

It will be understood that the fragmented plunger 80 of according to the present invention it can also be used with syringes that have hypodermic needles where the bridge of rupture breaks before the injection begins or after Injection completed. It will also be understood that a plunger with some curved arms out can be used without a part fragmentable / breaking.

Although they have described several characteristics of the present invention above, it is understood that the various features of the present invention can be used alone or in Any combination thereof. Therefore, this invention is not limited only to preferred embodiments specifically shown in this application.

Claims (7)

1. A plunger (80) and a fluid chamber (40), said plunger (80) moves by sliding inside the fluid chamber (40), and has proximal ends and distal with a flared part out adjacent to the end proximal thereof, whose piston (80) comprises a main body which has a proximal end and a distal end to expel the fluid outside or to introduce the fluid into the chamber (40) and a plurality of outwardly flared arms (82) located in the proximal end of the plunger (80), said arms flared towards out (82) configured to be operatively associated with a force generator component (72) for body movement main and being configured and sized to receive the part flared out in order to allow the release of the force generator component (72) from flare arms out (82). 2. A plunger (80) according to the Claim 1, where the arms flared out (82) they have an internal surface and an external surface and a edge portion (90) is located on the inner surface. 3. A plunger (80) according to the Claim 1 or 2, wherein the arms flared out (82) they have an edge part (94) located on the outer surface and that said flared portion out of the inner chamber (40) includes an annular groove (98) to receive the edge part (94). 4. A plunger (80) according to the Claim 2 or 3, wherein the force generating component (72) includes an end portion (88) and the edge portions (90) of the arms flared out (82) are located within the camera (40). 5. A set of nozzles (10) comprising the plunger (80) and the fluid chamber (40) according to all and each of the preceding claims 1 to 4 and adapted to use with an injection mechanism (30) where the distal end of the fluid chamber (40) has a hole (42) for the passage of the fluid. 6. A set of nozzles (10) according to Claim 5, wherein the plunger (80) is made of a acrylic polymer 7. A set of nozzles (10) according to Claim 5 or 6, wherein the plunger (80) is made of a material that includes a polymer selected from a group that It consists of poly carbonate, polypropylene, poly styrene and acrylic.